.add-box{
    position: fixed;
    text-align: center;
    line-height: 50px;
    left: 40%;
    top: 30%;
    bottom: 0;
    right: 0;
    width: 400px;
    height: 300px;
    border: 1px solid #000;
    background-image: url(https://ts1.cn.mm.bing.net/th?id=OIP-C.wO0Mho0j33uPg9cAr3UN3gHaEo&w=316&h=197&c=8&rs=1&qlt=90&o=6&dpr=1.5&pid=3.1&rm=2);
}
.btn{
    width: 150px;
    height: 50px;
    
}
td{
    border: 1px solid #000;
    text-align: center;width: 150px;height: 50px;
    
}
table{
    border-collapse: collapse;
}
td input{
    width: 150px;
    height: 50px;
}